With the advent of increasingly sophisticated telecommunication services, various proposals have been made to allow a single call, incoming to a telecommunication switch, to branch into multiple, independent outgoing calls (or legs) to different called parties, during the same period of time. These incoming and multiple outgoing calls may be wireline, such as PSTN (public switched telephone network), ISDN (integrated services digital network), or T1/E1 wireline calls, or may be wireless, such as cellular calls or other mobile service communications.
Once such proposal is included in the ANSI-41 specification promulgated by the American National Standards Institute for wireless telecommunication, such as cellular communication, and is referred to as "flexible alerting". The ANSI-41 flexible alerting specification, however, does not include any specific directions or guidelines for implementation and control of such independent, concurrent outgoing multiple leg calls.
Other prior art systems also do not provide for multiple outgoing calls, to different parties, during the same time period. Rather, such known systems provide for individual, sequential calls rather than multiple, concurrent outgoing calls. For example, the incoming call may first alert a home telephone having a first directory number; if the first call is unanswered, that call leg is dropped and a second telephone having a different, second directory number is alerted, such as a cellular phone. If the second call is unanswered, that second call leg is dropped, and a third line having a third directory number is alerted, such as a pager.
As a consequence, a need remains for an apparatus, method and system to implement and control multiple, independent outgoing communication sessions (or call legs) originating from a single incoming call leg. Such an apparatus, method and system should also provide for controlling the start of alerting, such as providing concurrent or simultaneous alerting, of the multiple, independent outgoing communication legs or links. Such an apparatus, method and system should be user friendly and user transparent. Such an apparatus, method and system should also be dynamic and responsive to changing environmental and user conditions which may arise in wireless or wireline communication systems.